Iron-containing atmospheric aerosols in the Chernobyl fallout

Mössbauer spectroscopy was applied to determine the composition and the iron concentration in the atmospheric aerosols contaminated in Sofia, Bulgaria after the Chernobyl accident. The results confirm the major conclusion of the Kopcewiczs for Poland, i.e. that in the initial filters, collected during the contaminating fallout (30.04-05.05.1986), the iron concentration was highest, 3.69 μg/m³ and that magnetite Fe₃O₄ was present. For the following days a change in the chemical composition including the presence of α-Fe₂O₃, α-FeOOH and γ-FeOOH as well as the absence of magnetite, was detected. Input of industrial iron contamination was negligible since the nearby steel plant had worked at minimum power due to official holidays. Unfortunately, Mössbauer spectroscopy studies only, do not allow a definite conclusion about an increase of the isotope abundance of ⁵⁷Fe in the Chernobyl fallout.